Assuming that such variables as gear ratio, vehicle weight, and driving habits remain unchanged, the 235 with its increased torque should spend more time running in the "economy" mode with the power valve closed due to higher intake manifold vacuum. That should result in slightly better gas mileage, although the difference might be hard to see. If you average fuel comsumption over at least a 3-month time frame, accounting for all driving conditions and weather changes, that's about the only way to get a true picture of fuel economy. Short-term checks just don't include enough of a diversity of conditions or length of time to be very accurate.
Jerry
